There are numerous domain name registrars. Listed below are just a few, along with my comments, if I know anything about them. Note that the domain name industry is highly competitive, with prices wildly fluctuating throughout the year, every year, so it's impossible to really mention accurate prices below unless I spend all my time updating this page. Please check their sites for the latest rates. All prices below are in US dollars.

Not every registrar sells every top-level domain, so if you want an uncommon TLD like .pizza, you might have to try a few registrars. Unusual TLDs often cost more than a standard .com address, but provide built-in memorability and give you more name options, since far fewer .pizza addresses are already taken. You can check name availability at any registrar that offers the TLD you want.
What’s easy to forget, though, is that Verisign have managed .com for the past 20 years without so much as a hiccup of disruption or downtime, and that there’s no guarantee that a more democratic or competitive process would have resulted in the 2 decades of .com stability that we’ve enjoyed. Internet governance is obviously important, but we should remember that the overwhelming majority of users don’t know or care what’s going on behind the scenes.
1&1 makes buying your domain name simple. The more complicated part is on your end in figuring out what you want your domain to be named. Once you have figured out what you want your domain name to be, 1&1 helps you with the rest. When you purchase a domain with 1&1, the cost is inclusive all the registration fees and affiliated E-Mail accounts with 2 GB storage space. Choose a domain package you need, and the registration is free. It includes sub-domains, a control panel, E-Mail account and support. Furthermore you use the website builder provided to you by 1&1 to construct your own website around your new domain.
If you do not have a web host, you can always allow the registrar to park your domain name at a temporary website specially set up for you. This way you can quickly secure your domain name before it's too late and still take your time to set up the other aspects of your site. As far as I can tell, most registrars (or probably all) automatically park your domain by default whether you ask them to or not, so if this is your situation, you probably don't have to do anything special to get it done. Some of those registrars also provide you with a free email address at your own domain name while it is parked at their site, like (where "" is your domain).

GoDaddy used to be a place I'd recommend only as a joke, but has significantly improved their service. They'll recommend you domains based on certain keywords, which is useful if you've not got the one you want available (they'll actually remove these from the search to try and not break your heart), and they've also significantly improved their hosting offering. They still continue to offer weird things like "email services" that other hosting companies provide too.  Our GoDaddy Review.

If you already have a web host, obtain from them the names of their primary and secondary nameservers. Don't worry if you don't understand what these things mean. Just save the information somewhere. The information can usually be obtained from their FAQs or other documentation on their site, usually under a category like "domain name" or "DNS" or "domain name transfer" and the like. If you can't find it, email them. You'll need the information to point your domain name to your website after you buy your domain. Having said that, if you don't have a web host yet, don't worry. Just read on.

I’ve tried to be charitable to Verisign in my reading of Site-Finder-gate. Even then it seems quite clear that they were deep within the grey areas of their contract with ICANN, and that they knowingly acted against the spirit of the Internet that they’d been entrusted to build. That said, I respect the hustle — Verisign were, and continue to be, a publicly traded company with a responsibility to deliver value to their shareholders, and this quasi-bait-and-switch was a pretty inspired way to do it.
A domain name is, quite simply, the name of your website. The domain can be found in the URL and is used in order to locate the website of a specific person or organization. Each domain name or URL directs users to a specific IP address. Domains are easier to remember than a long and complicated IP address, which takes the form of a series of numbers. A domain can be divided up into three different elements: a subdomain, a domain name, and a top level domain (TLD). Take as an example: the 'about' element is the subdomain, the '1and1' element is the domain name itself and the '.com' part of the URL is the top level domain. It is also possible to have multiple subdomain levels, for example, which you can use to segment your website into separate categories. The length limit of a complete domain name is 255 characters. With 1&1, you can choose a domain name that best suits you or your business, or you can transfer an already existing domain over to 1&1. Next, customers can select a TLD from a wide variety of domain extensions on offer. When choosing a domain name, it is important to select something that properly reflects the ethos of your business in a concise and catchy way. A good domain should be memorable, brandable, and should have a suitable extension.
Domain names disappear extremely fast. Many people claim that all the good domain names are gone. I doubt that — but it is probably true that most good domain names that are descriptive of products and services have been taken. If you want a domain name for your site, I suggest you act now, or face the anguish of having lost that name later. After all, US$10 (more or less) for a year's ownership of the name is rather cheap when you realise that you're securing a good name for your website.
For the most part, you can pick whichever TLD you prefer, though a few have restrictions -- you can't buy a .edu domain unless you run an accredited post-secondary school. Many, but not all, country-specific domains (.us, .uk, .jp) are restricted to citizens of the country in question. Unrestricted country domains are often used for "domain hacks," where the extension becomes part of the title, such as YouTube's alternate address, ""
Registrars offer a wide variety of registration durations—one year, three, five, and even ten. Be careful about registering for more than a year, though. First, there might be restrictions on your ability to transfer the domain name should the registrar give poor service. Second, the registrar could go out of business, leaving your domain name without a host. Check the policies closely.

Domain names are often seen in analogy to real estate in that domain names are foundations on which a website can be built, and the highest quality domain names, like sought-after real estate, tend to carry significant value, usually due to their online brand-building potential, use in advertising, search engine optimization, and many other criteria.

In order to register any domain, you must provide certain personal information that you may not wish to be publically searchable in the Whois database. Signing up for WhoisGuard is a great way to keep your registration data private. WhoisGuard acts as a "shield" for your searchable information, displaying the address, phone number, and email of the domain registrar (Namecheap, e.g.) instead of your own. Keep in mind that WhoisGuard is an optional security add-on that must be renewed separately when you renew your domain.